Association of cystatin C with left ventricular structure and function: the Dallas Heart Study.

BACKGROUND Cystatin C, a novel marker of renal function, has been associated with heart failure and cardiovascular mortality in older individuals. We tested the hypothesis that cystatin C is associated with preclinical cardiac structural and functional abnormalities in a younger population-based sample. METHODS AND RESULTS The study included participants in the Dallas Heart Study (ages 30 to 65 years) who had measurements of cystatin C and cardiac MRI. The associations of cystatin C with left ventricular (LV) mass, LV end-systolic and -diastolic volumes, concentricity (LV mass/LV end-diastolic volume), LV wall thickness, and LV ejection fraction were evaluated. Cystatin C levels ranged from 0.46 to 6.55 mg/L. In univariable analyses, increasing levels of cystatin C correlated with higher LV mass, concentricity, and wall thickness (P<0.001), but not with LV end-systolic volume, LV end-diastolic volume, or LV ejection fraction. After adjustment with traditional covariates and estimated glomerular filtration rate by the modification of diet in renal disease formula, log-transformed cystatin C remained independently associated with LV mass (P<0.001), concentricity (P=0.027), and wall thickness (P<0.001). These associations persisted when creatinine or estimated glomerular filtration rate by the Cockcroft-Gault formula were included in the models. CONCLUSIONS Higher levels of cystatin C were associated with increased LV mass and a concentric LV hypertrophy phenotype. These findings were independent of potential confounding variables including standard measurements of renal function, supporting the hypothesis that cystatin C may be useful to identify individuals with preclinical structural heart abnormalities.